1. Field of the Invention
The present invention relates to a ground rodent repeller; in particular, to a repeller for repelling rodents by using audio frequencies.
2. Description of Related Art
Since ground rodents (such as groundhogs) like to dig the soil around roots of crop plants and tunnel extensive burrows, the growth of plants is directly damaged, and inhabitance of pests and rats are likely attracted, further causing plant diseases, creating losses and troubles for farmers. In current techniques, sound waves can be emitted at regular intervals to drive away underground rodents, thereby achieving the object of repelling rodents.
For example, Publication TW 303600 discloses a “Groundhog Repeller with Easily Replaceable Battery,” including: a tube, an installation frame slidably disposed therein, a repeller unit disposed on the installation frame, and a top cover covering the top opening of the tube. A connection piece is connected between the top cover and the installation frame, enabling the installation frame to be pulled out of the tube in conjunction with the top cover, facilitating the replacing of battery of the repeller unit. Additionally, a screw passes through the top cover and a nut fixes the connection piece onto the underside of the top cover. Additionally, a handle is disposed at the head of the screw, and lies flat on the top cover when not in use so as to reduce its height of protrusion.
However, the groundhog repeller requires the handle to be turned about ten to twelve seconds during operation in order to loosen the screw with the nut, so that the top cover, waterproof pad and the tightening piece are loosened with gaps in between them, allowing a human hand to apply force on the handle to pull out the installation frame for battery replacement. The implication is that during operation, much time needs to be spent on turning the handle to form gaps between the various parts before they can be pulled out (because the top cover, waterproof pad and the tightening piece must be in a tightened state to be waterproof, the three components cannot be pulled out without first turning the handle to loosen the screw with the nut and gaps are formed between the three loosened components.)
Therefore, the groundhog repeller has a complicated and time consuming procedure for battery replacement, and a higher production cost due to the relatively high number of components. Moreover, the top cover, waterproof pad and tightening pad all have apertures for the screw to pass through. Since the device is installed outdoors for long periods of time and subject to indiscriminate weather, it is easily corroded. The constant tightening and loosening between the screw and the nut also causes wear. The aperture of the waterproof pad is easily stretched and deformed, eventually creating gaps for air and water to seep through and into the device, further leading to short-circuiting and corrosion of the circuit within the installation frame.
Hence, the present inventor believes the above mentioned disadvantages can be overcome, and through devoted research combined with application of theory, finally proposes the present disclosure which has a reasonable design and effectively improves upon the above mentioned disadvantages.